Liquid coating applicator



Oct. 22, 1963 J. L. BATTLE LIQUID coATING APPLICATOR INVENTOR.

JACK L. BATTLE,

AMW

Filed'Aug. s1, 1961 m, fr

l. lI

53 or 7l ATTORNEY.

United States Patent Oilice 3,108,024 Patented Oct. 22, 1963 3,108,024 LIQUID CGATING APPLCATR Jack L. Battle, Houston, Tex., assiguor, by mesne assignments, to Jersey Production Research Company, Tulsa, Gkla., a corporation of Delaware Filed Aug. 31, 1961, Ser. No. 135,304 3 Claims. (Cl. 118-408) This invention relates to liquid coating applicators, and more particularly to wireline apparatus for effectively and uniformly applying a coating `of liquid materials to the inside of pipe strings such as are employed in pipe lines and in oil and gas wells.

Pipe strings employed in the production of oil and gas from wells and in transporting earth fluids -to remote locations often are deleteriously affected by the chemical action of fluids passing therethrough. Various expedients have been used to minimize damage to such pipe strings. For example, various compositions of liquid materials have been applied to the inner surfaces of pipes for inhibiting corrosion. Additionally, it is known to apply plastic coatings to the inner surfaces of pipe strings to insulate the pipe strings from the corrosive action of the iluids. During the productive life of the wells, the effectiveness of the corrosion inhibitor may be reduced, or the plastic coatings may be damaged during workover operations. Therefore, it is desirable to apply protective plastic or inhibitor coatings to the inner surfaces of pipe lines and well pipes, or to remove such coatings, while the pipes are in operative position in a well bore or pipe line. An example of prior art apparatus for this purpose is that described in U.S. Patent No. 2,941,500 to J ohn G. Adams.

A disadvantage associated with prior art apparatus is that it is not possible to effectively control the rate at which liquid materials are applied to the inner surfaces |of a pipe string through which the 'apparatus is drawn. Often an unnecessarily large amount o-f fluid is expended and the total time required for a coating operation is unnecessarily long.

1n accordance with one aspect of the present invention, there is provided a body member or housing including closure means for defining rat least one iluid reservoir means therewithin. Discharge means yare provided for permitting fluid egress from the fluid reservoir means ot the exterior of the housing. Plunger means in the iluid reservoir means for forcing reservoir iiuid through the discharge means has connected thereto apparatus for moving the plunger in `accordance with the movement tof. the housing through ya pipe string. Preferably, this apparatus comprises a rack and pinion driven by a roller member supported within the housing Iso that the number of revolutions thereof is proportional to the speed at which the housing is drawn through a pipe string to be coated. The invention Ifurther contemplates the inclusion of apparatus for urging the roller member into engagement with the inner walls of a pipe when the housing is at a selected position in the pipe. Such apparatus preferably comprises roller means hingedly affixed at one end of a Ksleeve or tube around the end of the housing opposite the reservoir means, inclined surface means on the housing -for urging the roller means radially outwardly from the housing as the sleeve and the housing move in telescoping relationship, and restraining means supported on the housing for urging the roller means against the inclined `surface means.

Objects and features of the invention not apparent from the above discussion will become evident upon consideration of the following detailed description thereof taken in connection with the accompanying drawing, wherein:

FIGS. 1 and 2A are partial cross-sectional views of a portion of the apparatus in accordance with the invenltion, showing two operating positions thereof with the apparatus illustrated in position in a well pipe;

FIG. 2B is :a partial cross-sectional view of the remainder of the apparatus, illustrated in the operative position of FIG. 2A;

FIG. 3 is a cross-sectional View taken along section 3-3 of FIG. 2A; and

FIG. 4 is a cross-sectional lView taken along either of sections 4 4 of FIG. 2B.

With reference now to the figures, generally, and particularly to FIGS. 1, 2A, and 2B, the invention is illustrated as being positioned i-n a well pipe string 1 which may be either =a tubing string or a casing string positioned in a well bore in the usual manner. A housing or body member comprises a plurality of sections 11, 23, 29, 45, 51, 53, 66, 68, 71, 82, and `S5 screw-threaded together in the recited order. The uppermost housing section 11 is aliixed to a cable head 9 to which cable head is attached a wireline 5 for lowering the apparatus into pipe string 1 `and .for withdrawing it therefrom. The sections 53, 71, and may be regarded as closure means which, along with housing lsections 66 and 82, deline liluid reservoirs 65 and 81. The housing sections 53 and 71 include therewithin a plurality of passageways designated by reference numerals 61 and '73, respectively, for the two sections (see both FIGS. 2B and 4), through which fluids within reservoirs 65 and 81 are discharged to the exterior of the housing. The discharge means further include annular sealing means 57, 59, 75, and 77 radially extending outwardly from the housing sections 53 and 71 on either side yof each of the passageways 61 and 73 so :as to conduct huid to the inner surface of well pipe 1. The sealing means may be formed of any suitable flexible or resilient material so that they will resiliently and wipingly engage the inner wall of pipe `string 1 to thus establish partially sealed zones therebetween through which fluids may be discharged to contact the inner wall of the pipe string 1.

Plunger means 67 and 83 in reservoirs 65 and 81, respectively, are `for the purpose of forcing reservoir iluids out of the reservoirs and through the discharge passageways 61 and 73. 'Il-he plunger means should conform to the inside of the housing sections 66 and 82;, respectively, and may include annular sealing rings thereon to eiect sealing engagement with the inner walls of the housing sections 66, 82. Filling ports are provided at the upper ends of the fluid reservoir-s, which ports are closed by screw plugs 63, 79.

Relief passageways 69 and 87 in housing `sections 68 and 8S, respectively, are provided for fluid relief so that the plungers 67 and 8'3 may move freely through the reservoirs 65, 81.

A hollow plunger rod 49 having ports 49a connects together plungers 67 and 83 so that the plungers are simultaneously moved in reservoirs 65 and 81, and further connects the plungers to the lower end of a rack member 43. The rack member extends through housing sections 45 and 29 and is reciprocally movable therein so as to simultaneously move piston members 67 and 83 between the extremities of reservoirs 65 and 81. A pinion gear 42 meshes with the teeth 44 of rack 43 to thus bidirectionally move the rack. The pinion gear 42 is connected to a wheel vor roller member 41 either directly or through a reducing gear train. The roller means extends through a port or opening in housing section 29 so as to contact the inner surface of pipe 1. As the roller member 41 rolls along the inner surface tof pipe 1 when the housing is drawn up through the pipe string, gear 42 will be rotated so as to move the rack member 43 upwardly through the housing. While the roller member 41 is shown as being directly connected to the pinion gear 42,

preferably a reducing gear train is used so that the rack member 43 is moved relatively slowly as the housing is drawn through the pipe string. Both the roller member 41 and pinion gear 42 are supported within the housing, as is most perspicuously illustrated in FIG. 3. Ports 5@ in housing section 45 provide fluid communication between the well bore and the housing section 45 to permit fluid passage through the apparatus as it is lowered through the well bore.

When the gear 42 and rack `43 are in the running-in position shown in FIG. 1, plunger 83 rests on end section S5 so that the gear 42 does not run off the end of rack 43.

It is desirable that the housing be lowerable through the pipe string relatively quickly, which requires that the roller member 41 not be urged against the inner wall of the pipe string while the housing is being lowered thereA through. However, it is requisite that the roller member 41 be continuously and firmly urged against the pipe string while the housing is being withdrawn from the pipe string during the time interval that fiuids are being discharged from the fluid reservoirs. For this purpose there is provided a sleeve member comprising sleeve sections 17, 25, and 27 which surround the upper portion of the housing, specifically housing sections 11, 23, and 29. The sleeve member and housing sections are adapted to move in partial telescoping relationship and are normally urged apart by a spring 31 disposed between a shoulder 2S formed by the lower end of housing section 23, and an internal shoulder 32 near the lower end of sleeve section 27. At the lower end of sleeve section 27 there is hingedly connected a plurality of arms 33 extending downwardly from sleeve section 27, to which are axed roller members 35. A plurality of inclined surfaces 37 are provided on housing section 29 opposite roller member 41 and pinion gear 42. The inclined surfaces are shown extending outwardly and downwardly so that as each roller member 35 is moved downwardly, it will be urged outwardly into engagement with the inner wall of pipe 1. An annular spring member 39 in a groove 38 at the lower end of housing `section 29 engages the arms 33 to urge the lower ends thereof against the inclined sunfaces 39. Thus, when the sleeve member is moved downwardly, the arms 33 will pivot so that the roller members 35 will be moved into engagement with the inner wall of pipe 1 as arms 33 slide along the inclined surfaces 37.

The sleeve member and 'housing are releasably connected together by ball detent means comprising an annular groove 13 in housing section 11 and a ball 15 adapted to fit through a `hole or port in sleeve section 17 so as to connect together the two members.

For the purpose of controlling the movement of the sleeve that is in telescoping relationship with the housing,l there is provided an outer sleeve 7 surrounding the upper end of sleeve section 17. A coil spring 19 surrounding the lower end of sleeve section 17 is positioned between a shoulder 20 of sleeve section 17 and the lower end of outer sleeve '7. An internal recess 12 in outer sleeve 7 has an enlarged portion at the upper end thereof so that ball may slide out of groove 13 to disconnect sleeve section 17 from housing section 11.

The fluid reservoirs described above preferably are filled with a normally liquid plastic composition in one reservoir and a hardener or catalyst for the plastic composition in the other reservoir. mally liquid plastic composition may be an epoxy resin and the catalyst or hardener may be a suitable acid anhydride or amine such as pyromellitic dianhydride, dimethyl amino `methyl phenol, diethylene triamine, and phthalic dianhydride. At the lower end of rack 43 there is a short space 44a, above which the teeth 44 terminate. The gear 42 is adapted to move into this short space so as to freewheel therewithin. Recess 47 (see FIG. 2B) is adapted to receive a ball member 46 (see FIG. 3) which is biased by spring 48 4into the recess 47. A spring- For example, the nor-` holding member 48a holds the spring and is adapted to be inserted into and screw-threadedly withdrawn from `housing section Z9. There is thus provided apparatus for permitting the gear 42 and roller member 41 to freewheel after all of the fluid has been forced out of reservoirs 65 and 81fso that the apparatus may be rapidly withdrawn from the well.

The modus operandi of the above-described apparatus is as follows: An appropriate plastic composition or other desired pipe treating liquid is injected into reservoir 65, and a hardener therefor or other liquid is injected into reservoir 81, after which plugs 63 and 79 are screwed into the appropriate ponts to seal Ithe reservoirs. Manifestly, the plungers 67 and 83 must be at the lower ends of the reservoirs during this operation. The apparatus manifestly will be in the position shown in FIG. l. With the apparatus in the position shown in FIG. l, the spring 31 will be under compression and the housing and sleeve member will be locked together. The apparatus is thereupon lowered to the lowermost position in the pipe string from which it is desired to apply pipe treating liuids.

An annular go-devil 3 (see FIG. 2A) is thereupon dropped into the pipe string. When the go-devil strikes the outer sleeve 7, the outer sleeve will be driven down into Ithe position shown in FIG. 2A. The ball 15 will pop out of groove 13 into the enlarged upper portion of recess 12. Spring 19 will be placed under compression and will drive the sleeve sections 17, 25, and 27 downwardly relative to (the housing sections. Roller members 35 vw'll be driven downwardly along the inclined surfaces 37 corresponding thereto and into engagement with the inner wall of pipe 1. Roller member 41 now will be in firm engagement with the inner wall of the pipe 1. The apparatus may then be withdrawn upwardly through the well so that vgear 42 will drive rack 43 and plungers 67 and 83 upwardly. Fluid will flow from reservoirs 65 and 81 proportional to the rate of withdrawal of the apparatus up the pipe string. Wheln the fluid is exhausted, the gear will be below the bottom of the rack, ball 46 will pop into recess 47, and the apparatus may be rapidly withdrawn up the pipe string so that the reservoirs may again be filled with liquid and the operation repeated. The depth at which the tension on the line falls off should be noted so that the next treating operation may begin at that level.

The invention is not to be restricted to Ithe specific structural details or arrangement of pants herein set forth, as various modifications thereof may be effected without departing from the spirit and scope of this invention;

The objects and features of the invention having been completely described, what I wish to claim is:

1. Apparatus for coating the interior surface of a pipe with a thin liquid film, comprising:

an elongated housing having a diameter such that the housing is slidable through the pipe to be coated, said housing including closure means defining fluid reservoir means therewithin;

plunger means in said reservoir means;

a plunger rod secured Ito said plunger means for moving said plunger means through said reservoir means;

discharge means extending through said 'housing to establish fluid ycommunication between said reservoir means at one end thereof and the exterior of said housing;

an elongated rack connected to said plunger rod;

a pinion gear supported in said housing, meshing with said rack for longitudinally moving said plunger rod through said reservoir means upon rotation of said pinion gear; and

means supported in said housing, operatively connected to said pinion gear for rotating said pinion gear in proportion to movement of said housing through the pipe to be coated.

2. Apparatus for coating the interior surface of a pipe with a thin liquid film, comprising:

an elongated housing having a diameter such that the housing is slidable through the pipe to be coated, said housing including closure means dening Huid reservoir means therewithin;

plunger means in said reservoir means;

a plunger rod secured to said plunger means rior mov ing said plunger means through said reservoir means;

discharge means extending through said housing to establish iiuid communication between said reservoir means at one end thereof and the exterior lof said housing;

an elongated rack connected to said plunger rod;

a pinion gear supported in said housing, meshing with said rack for longitudinally moving said plunger rod through said reservoir means upon rotation of said pinion gear;

roller means supported in said housing, operatively connected to said pinion gear for rotating said pinion gear in proportion to movement of said housing through the pipe to be coated; and

means connected to said housing for urging said roller means into engagement with the inner wall of the pipe.

3. Apparatus for coating the interior surface of a pipe with a thin liquid film, comprising:

an elongated housing having a diameter such that the housing is slidable through the pipe to be coated, said housing including closure means defining liuid reservoir means therewithin;

plunger means in said reservoir means;

a plunger rod secured to said plunger means for moving said plunger means through said reservoir means; discharge means extending through said housing to establish fluid ycommunication between said reservoir means at one end thereof and the exterior of said housing;

an elongated rack cemented to said plunger rod;

a pinion gear supported in said housing, meshing with said rack for longitudinally moving said plunger rod through said reservoir means upon rotation or said pinion gear;

roller means supported in said housing, operatively connected to said pinion gear :for rotating said pinion gear in proportion to movement of said housing through the pipe to be coated;

means `connected to said housing for urging said roller means into engagement with the inner wall of the rupe;

said last-named means comprising a sleeve member slidable' over a portion of said housing and in partial ytelescoping relationship therewith, at least one roller "member, arm means supporting each said at least one roller member, said arm means being pivotally supported on said sleeve member; and

restraining means for urging said arm means inwardly 'toward said housing, at least one inclined surface on said housing positioned to receive said roller member to urge said roller member outwardly from said housing as said sleeve member and said housing move together in telescoping relationship to urge said roller member into engagement with the inner wall of the pipe, spring means engaging said housing and said sleeve member to urge said housing and said sleeve member together in telescoping relationship and means for releasably holding said sleeve member and said housing at a predetermined relative position thereof whereat said roller means is held away from the walls of the pipe by said restraining means.

References Cited in the le of this patent UNITED STATES PATENTS 2,941,500 Adams lune 2l, i960 

1. APPARATUS FOR COATING THE INTERIOR SURFACE OF A PIPE WITH A THIN LIQUID FILM, COMPRISING: AN ELONGATED HOUSING HAVING A DIAMETER SUCH THAT THE HOUSING IS SLIDABLE THROUGHT THE PIPE TO BE COATED, SAID HOUSING INCLUDING CLOSURE MEANS DEFINING FLUID RESERVOIR MEANS THEREWITHIN; PLUNGER MEANS IN SAID RESERVOIR MEANS; A PLUNGER ROD SECURED TO SAID PLUNGER MEANS FOR MOVING SAID PLUNGER MEANS THROUGH SAID RESERVOIR MEANS; DISCHARGE MEANS EXTENDING THROUGH SAID HOUSING TO ESTABLISH FLUID COMMUNICATION BETWEEN SAID RESERVOIR MEANS AT ONE END THEREOF AND THE EXTERIOR OF SAID HOUSING; AN ELONGATED RACK CONNECTED TO SAID PLUNGER ROD; A PINION GEAR SUPPORTED IN SAID HOUSING, MESHING WITH SAID RACK FOR LONGITUDINALLY MOVING SAID PLUNGER ROD THROUGH SAID RESERVOIR MEANS UPON ROTATION OF SAID PINION GEAR; AND MEANS SUPPORTED IN SAID HOUSING, OPERATIVELY CONNECTED TO SAID PINION GEAR FOR ROTATING SAID PINION GEAR IN PROPORTION TO MOVEMENT OF SAID HOUSING THROUGH THE PIPE TO BE COATED. 